39 research outputs found
An intriguing shift occurs in the novel protein phosphatase 1 binding partner, TCTEX1D4: evidence of positive selection in a pika model
T-complex testis expressed protein 1 domain containing 4 (TCTEX1D4) contains the canonical phosphoprotein phosphatase 1 (PPP1) binding motif, composed by the amino acid sequence RVSF. We identified and validated the binding of TCTEX1D4 to PPP1 and demonstrated that indeed this protein is a novel PPP1 interacting protein. Analyses of twenty-one mammalian species available in public databases and seven Lagomorpha sequences obtained in this work showed that the PPP1 binding motif 90RVSF93 is present in all of them and is flanked by a palindromic sequence, PLGS, except in three species of pikas (Ochotona princeps, O. dauurica and O. pusilla). Furthermore, for the Ochotona species an extra glycosylation site, motif 96NLS98, and the loss of the palindromic sequence were observed. Comparison with other lagomorphs suggests that this event happened before the Ochotona radiation. The dN/dS for the sequence region comprising the PPP1 binding motif and the flanking palindrome highly supports the hypothesis that for Ochotona species this region has been evolving under positive selection. In addition, mutational screening shows that the ability of pikas TCTEX1D4 to bind to PPP1 is maintained, although the PPP1 binding motif is disrupted, and the N- and C-terminal surrounding residues are also abrogated. These observations suggest pika as an ideal model to study novel PPP1 complexes regulatory mechanisms.publishe
Ultrastructural, Antigenic and Physicochemical Characterization of the MojuĂ dos Campos (Bunyavirus) Isolated from Bat in the Brazilian Amazon Region
Depressive symptoms and harmful alcohol use in hepatitis C patients: prevalence and correlates
Chagasic Thymic Atrophy Does Not Affect Negative Selection but Results in the Export of Activated CD4+CD8+ T Cells in Severe Forms of Human Disease
Extrathymic CD4+CD8+ double-positive (DP) T cells are increased in some pathophysiological conditions, including infectious diseases. In the murine model of Chagas disease, it has been shown that the protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironment and the lymphoid compartment. In the acute phase, this results in a severe atrophy of the organ and early release of DP cells into the periphery. To date, the effect of the changes promoted by the parasite infection on thymic central tolerance has remained elusive. Herein we show that the intrathymic key elements that are necessary to promote the negative selection of thymocytes undergoing maturation during the thymopoiesis remains functional during the acute chagasic thymic atrophy. Intrathymic expression of the autoimmune regulator factor (Aire) and tissue-restricted antigen (TRA) genes is normal. In addition, the expression of the proapoptotic Bim protein in thymocytes was not changed, revealing that the parasite infection-induced thymus atrophy has no effect on these marker genes necessary to promote clonal deletion of T cells. In a chicken egg ovalbumin (OVA)-specific T-cell receptor (TCR) transgenic system, the administration of OVA peptide into infected mice with thymic atrophy promoted OVA-specific thymocyte apoptosis, further indicating normal negative selection process during the infection. Yet, although the intrathymic checkpoints necessary for thymic negative selection are present in the acute phase of Chagas disease, we found that the DP cells released into the periphery acquire an activated phenotype similar to what is described for activated effector or memory single-positive T cells. Most interestingly, we also demonstrate that increased percentages of peripheral blood subset of DP cells exhibiting an activated HLA-DR+ phenotype are associated with severe cardiac forms of human chronic Chagas disease. These cells may contribute to the immunopathological events seen in the Chagas disease
Expanding the knowledge about Leishmania species in wild mammals and dogs in the Brazilian savannah
Background: Wild, synanthropic and domestic mammals act as hosts and/or reservoirs of several Leishmania spp. Studies on possible reservoirs of Leishmania in different areas are fundamental to understand host-parasite interactions and develop strategies for the surveillance and control of leishmaniasis. In the present study, we evaluated the Leishmania spp. occurrence in mammals in two conservation units and their surroundings in BrasĂlia, Federal District (FD), Brazil. Methods: Small mammals were captured in BrasĂlia National Park (BNP) and Contagem Biological Reserve (CBR) and
dogs were sampled in residential areas in their vicinity. Skin and blood samples were evaluated by PCR using different molecular markers (D7 24Sα rRNA and rDNA ITS1). Leishmania species were identified by sequencing of PCR products. Dog blood samples were subjected to the rapid immunochromatographic test (DPP) for detection of anti-Leishmania infantum antibodies. Results: 179 wild mammals were studied and 20.1% had Leishmania DNA successfully detected in at least one sample. Six mammal species were considered infected: Clyomys laticeps, Necromys lasiurus, Nectomys rattus, Rhipidomys macrurus, Didelphis albiventris and Gracilinanus agilis. No significant difference, comparing the proportion of individuals with Leishmania spp., was observed between the sampled areas and wild mammal species. Most of the positive samples were collected from the rodent N. lasiurus, infected by L. amazonensis or L. braziliensis. Moreover, infections by Trypanosoma spp. were detected in N. lasiurus and G. agilis. All 19 dog samples were positive by DPP; however, only three (15.8%) were confirmed by PCR assays. DNA sequences of ITS1 dog amplicons showed 100% identity with L. infantum sequence. Conclusions: The results suggest the participation of six species of wild mammals in the enzootic transmission of Leishmania spp. in FD. This is the first report of L. amazonensis in N. lasiurus
Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns
This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela â Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa
Randomized controlled trial of a coordinated care intervention to improve risk factor control after stroke or transient ischemic attack in the safety net: Secondary stroke prevention by Uniting Community and Chronic care model teams Early to End Disparities (SUCCEED)
BACKGROUND: Recurrent strokes are preventable through awareness and control of risk factors such as hypertension, and through lifestyle changes such as healthier diets, greater physical activity, and smoking cessation. However, vascular risk factor control is frequently poor among stroke survivors, particularly among socio-economically disadvantaged blacks, Latinos and other people of color. The Chronic Care Model (CCM) is an effective framework for multi-component interventions aimed at improving care processes and outcomes for individuals with chronic disease. In addition, community health workers (CHWs) have played an integral role in reducing health disparities; however, their effectiveness in reducing vascular risk among stroke survivors remains unknown. Our objectives are to develop, test, and assess the economic value of a CCM-based intervention using an Advanced Practice Clinician (APC)-CHW team to improve risk factor control after stroke in an under-resourced, racially/ethnically diverse population. METHODS/DESIGN: In this single-blind randomized controlled trial, 516 adults (â„40Â years) with an ischemic stroke, transient ischemic attack or intracerebral hemorrhage within the prior 90Â days are being enrolled at five sites within the Los Angeles County safety-net setting and randomized 1:1 to intervention vs usual care. Participants are excluded if they do not speak English, Spanish, Cantonese, Mandarin, or Korean or if they are unable to consent. The intervention includes a minimum of three clinic visits in the healthcare setting, three home visits, and Chronic Disease Self-Management Program group workshops in community venues. The primary outcome is blood pressure (BP) control (systolic BP <130Â mmHg) at 1Â year. Secondary outcomes include: (1) mean change in systolic BP; (2) control of other vascular risk factors including lipids and hemoglobin A1c, (3) inflammation (C reactive protein [CRP]), (4) medication adherence, (5) lifestyle factors (smoking, diet, and physical activity), (6) estimated relative reduction in risk for recurrent stroke or myocardial infarction (MI), and (7) cost-effectiveness of the intervention versus usual care. DISCUSSION: If this multi-component interdisciplinary intervention is shown to be effective in improving risk factor control after stroke, it may serve as a model that can be used internationally to reduce race/ethnic and socioeconomic disparities in stroke in resource-constrained settings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01763203
Desigualdades sociais, polĂticas de saĂșde e formação de mĂ©dicos, enfermeiros e dentistas no Brasil e em Portugal
Ultrastructural, Antigenic and Physicochemical Characterization of the MojuĂ dos Campos (Bunyavirus) Isolated from Bat in the Brazilian Amazon Region
The Mojuà dos Campos virus (MDCV) was isolated from the blood of an unidentified bat (Chiroptera) captured in Mojuà dos Campos, Santarém, State of Parå, Brazil, in 1975 and considerated to be antigenically different from other 102 arboviruses belonging to several antigenic groups isolated in the Amazon region or another region by complement fixation tests. The objective of this work was to develop a morphologic, an antigenic and physicochemical characterization of this virus. MDCV produces cytopathic effect in Vero cells, 24 h post-infection (p.i), and the degree of cellular destruction increases after a few hours. Negative staining electron microscopy of the supernatant of Vero cell cultures showed the presence of coated viral particles with a diameter of around 98 nm. Ultrathin sections of Vero cells, and brain and liver of newborn mice infected with MDCV showed an assembly of the viral particles into the Golgi vesicles. The synthesis kinetics of the proteins for MDCV were similar to that observed for other bunyaviruses, and viral proteins could be detected as early as 6 h p.i. Our results reinforce the original studies which had classified MDCV in the family Bunyaviridae, genus Bunyavirus as an ungrouped virus, and it may represent the prototype of a new serogroup